The back up doesn’t take into account any start or end dates, as it’s a full account back up. Unfortunately, bringing the old report back would cause some issues and be demanding on our server resources (there’s more details on that in the post I linked to above).
However, if you use Excel or similar spreadsheet software, you can limit the range by using a filter.
Open the CSV file, select the filter option:
In Excel, you are given this option on date columns:
Hope that helps!